Hands up for your favourite x0x mods.
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Hands up for your favourite x0x mods.

by cleaninglady on Wed Jul 18, 2012 4:33 am

Here i am with a just completed x0x and i was just wondering what all of you thought were the top mods to go for.

Just listening to it , i have my ideas already ; I just want to hear yours...

Do your worst.
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Re: Hands up for your favourite x0x mods.

by antto on Wed Jul 18, 2012 5:17 am

if you want to keep it sounding like a 303 (and not like something much different) then i'd only suggest a few mods
1) resonance boost, a tiny bit..
2) reverse C29 .. not that it makes any huge difference, but it doesn't seems to hurt either
We are here too: irc.freenode.net >>> #x0xb0x
..:: c0nb0x v1.00 ::.. http://forums.adafruit.com/viewtopic.php?f=7&t=29282 (new control app - win/osx)
VCO Tuning: http://forums.adafruit.com/viewtopic.php?f=12&t=24759 (do it the EASY way)
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Re: Hands up for your favourite x0x mods.

by cleaninglady on Wed Jul 18, 2012 6:05 am

i totally agree about the res , just seems like it needs a tiny boost. What did you use values wise ?

what does the C29 capacitor reversal do ?
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Re: Hands up for your favourite x0x mods.

by antto on Wed Jul 18, 2012 6:53 am

for the reso boost mod, the easiest thing to do is replace R97 which is 10K originally
i use my x0x for scientific stuff, thus i have soldered wires and a 10K pot, but i will eventually figure something more elegant some day (still with a tweakable pot or trimmer)
something like 9K is fine-ish, but the best thing to do is take off R97, then put a 10K pot temporarily and run the x0x, tweak the pot till you get the best feeling of it, then measure the pot value and that's your resistance, you could still put a trimmer there

iirc bcbox (from this forum) discovered that probably in all 303s a capacitor is placed backwards - C29
the roland schematic shows it "correctly" it's negative leg goes to ground, same thing on the x0xb0x, BUT if you look inside a 303 you would probably see that the capacitor is with the positive leg to ground
C29 is in the VCF area
there's a big thread i think in the x0xm0dz forum if you wanna know more
We are here too: irc.freenode.net >>> #x0xb0x
..:: c0nb0x v1.00 ::.. http://forums.adafruit.com/viewtopic.php?f=7&t=29282 (new control app - win/osx)
VCO Tuning: http://forums.adafruit.com/viewtopic.php?f=12&t=24759 (do it the EASY way)
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Re: Hands up for your favourite x0x mods.

by antto on Wed Jul 18, 2012 6:55 am

actually, a better thing to do is to put sockets here and there IMO
like R97, Q8, C29..
We are here too: irc.freenode.net >>> #x0xb0x
..:: c0nb0x v1.00 ::.. http://forums.adafruit.com/viewtopic.php?f=7&t=29282 (new control app - win/osx)
VCO Tuning: http://forums.adafruit.com/viewtopic.php?f=12&t=24759 (do it the EASY way)
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